 <!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
	</body>
	<script type="text/javascript">
		//函数的提升优于变量的提升
		foo(); 
		var foo;
		function foo() {
			console.log( 1 );
		}
	</script>
</html>
